A.S. refers to 'Alayhis-salaam, (God's) peace be with him. It is said after the names of all previous prophets, their mothers (e.g. Bibi Maryam [Mary] A.S.), the twelve divine Imams from the household of Prophet Muhammad (S.A.W.) and Bib i Fatima (A.S.). It will change to 'Alayhas-salaam (peace be with her) if it follows a lady's name. After any two names we say 'Alayhimas-salaam and after more than two names or when referring a group of people we say 'Alayhimus-salaam. Thus, we sa y Imams Hasan and Husayn (A.S.='alayhimas-salaam) and the Ahul-Bayt (A.S.'alayhimus-salaam).